Fw: [aprssig] Telemetry question

Andrew Rich vk4tec at hotmail.com
Sat Aug 14 21:58:51 EDT 2004

1. baud rate is what ever - say 300 baud
2. One way data - half duplex
3. S/n ratio of voice channel is good - can see the other station

Someone must have passed data like this before packet handshaking was
invented ?
Dont care about syncup. - just send some rubbish
I have an ultralight right, and I want to send the position every second.
I have had thoughts of RF modules - you know rs232 in, RF out and vice
Surely car racing teams must use fast live telemetry ?
See I can parse anythign I want from a GPS, all I would like to send is
"RAW" data
Over a line of site path.
RTTY is just a shortened version of what I want to do, maybe I just use that
Surely there are telmetry units that just use RS232 - One tone for a high
and another for a low.

----- Original Message -----
From: "John Langtry, VE3NEC" <ve3nec at sympatico.ca>
To: "Andrew Rich" <vk4tec at hotmail.com>
Cc: <scott at opentrac.org>
Sent: Sunday, August 15, 2004 11:08 AM
Subject: Re: [aprssig] Telemetry question

Greetings Andrew,

You're not giving us very much technical data to make
recommendations from.

Quite apart from Scott's excellent thoughts about async.
vs sync data, other factors come into play.

What is the bit rate of the RS-232 data ?
Is the data path to be half or full duplex ?
What is the bandwidth and S/N ratio of the "voice channel" ?
If the "voice channel" is radio, depending on your bit rate,
twist and squeue come into play.

While the MX614 is a good chip in certain applications, in others
the AMD 7910 or 7911 chip might be a better choice. On the other
hand if parts count are not a consideration, you might be better
served with the good old fashioned XR2006 & XR2211 pair - the
list of possibilities are almost endless.

Very interested in your application. More details would be
helpful however. Always remember, "Nothing beats an experiment
like a failure." Meaning, by all means *try* the MX614 as an
experiment; because if you don't, you'll never know if it failed
in your application or not.

vy 73 de John VE3NEC
IRLP node # 2200

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